Alternatives Considered

70 ideas evaluated

The public, stakeholders and partner agencies identified six project area
problems which resulted in the
CRC Purpose and Need Statement. Based on this identified need, 70 ideas for
potential solutions were suggested and discussed by partner agencies, the
39-member CRC Task Force and the public in late 2005 and early 2006. The 70 components
consisted of river crossings types and locations, transit options, roadway improvements,
travel demand management programs and improvements to pedestrian and bicycle connections.
Evaluation criteria were developed by the Task Force during this time to help narrow these
options.

Evaluation criteria and screening process

Click to open a PDF of the above graphic.

Potential bridge and transit solutions were initially evaluated by project
staff and Task Force against the Purpose and Need Statement and whether they
could help address the problems. After the initial screening, the most promising
river crossing options and transit modes were paired with other components A smaller
set of ideas were combined into 12 representative alternatives in 2006.

Each representative alternative included several transportation
components: bridge, highway, transit, freight, bicycle and pedestrian
improvements, and strategies to reduce travel demand. The Task Force’s evaluation
criteria and stakeholder and public input were used to evaluate each alternative
on its technical merits. Based on this evaluation, a set of three alternatives were
proposed for analysis in the Draft Environmental Impact Statement. Modeling and analysis
showed alternatives without improvements to both the highway and transit system did not
address the Purpose and Need for the project.

CRC held extensive public discussions to gather comments on the proposal in
early 2007. With guidance from the CRC Task Force and the public, the number of
Draft EIS alternatives was increased to five to include alternatives that reused the
Interstate Bridge. The Draft EIS was released on May 2, 2008 for public and agency
review.

Locally preferred alternative selected

The six local project partners considered the Draft EIS findings, 1,600
public comments and the CRC Task Force recommendation to select a Locally
Preferred Alternative (LPA) in July 2008. The partner agencies endorsed a
replacement I-5 bridge, light rail extending to the Clark College area,
improvements to closely-spaced interchanges and enhancements to the bicycle and
pedestrian path.

Some of the options considered during this three year process included:

BRIDGE

Third highway river crossing

CRC studied new river crossings at
locations east and west of the I-5 corridor.

Between 68 and 75 percent of trips crossing the Interstate Bridge in peak
travel hours use an interchange in the project area to enter or exit I-5. As a
result, a new bridge constructed east or west of I-5, would not divert a large
volume of traffic to that new bridge and I-5 congestion would remain. In addition, a third river crossing would not
address the safety deficiencies on the Interstate Bridge or the highway leading
to it. The Southwest Washington Regional Transportation Council (RTC) has
studied the
future need for a third crossing outside the I-5 corridor.

Tunnel

CRC studied tunnel options to both replace the existing I-5 bridge and
supplement the bridge.

Matching the existing roadway grades on either side of the river with a
tunnel would be challenging due to the urban environment and water quality
issues. A tunnel would likely bypass at least three
interchanges in the project area: Vancouver City Center, SR 14 and Hayden
Island. A tunnel would require creating an intricate system of arterials east
and west of the tunnel for vehicles to access the portals in and out of the
structure. This system would have more water quality, right of way,
archaeological and historic resource impacts than the alternatives considered.

Arterial bridge

CRC studied two arterial bridge options: one connecting Vancouver to 33rd
Avenue in Portland and the other connecting downtown Vancouver to Hayden Island.

A new arterial bridge would carry only 13 to 18 percent of river crossing trips
and I-5 would continue operating over-capacity.
An arterial bridge would carry both local and regional trips. Traffic congestion
in downtown Vancouver would increase by about 60 percent as drivers backed up on
local streets trying to bypass I-5 across the Columbia River.

Upstream replacement I-5 bridge

CRC removed the replacement upstream bridge alignment from additional active
study because of its significant impacts to the Fort Vancouver National Historic
Reserve and its lengthier construction time compared to other bridge
alternatives. The upstream bridge alignment is discussed in the Draft
Environmental Impact Statement.

Supplemental I-5 bridge

CRC studied options for a new bridge upstream or downstream of the
existing I-5 bridge. The existing bridge would remain and carry a portion of
interstate traffic.

Analysis showed that a supplemental I-5 bridge for southbound vehicles would
not fully address safety and congestion problems in northbound travel lanes. The
operation and maintenance requirements of the existing bridges and lift span
would continue. Costly improvements would be needed on the existing bridges to
prevent damage in the event of a major earthquake.

CRC ruled out commuter rail on the Burlington Northern-Santa Fe tracks
because the system does not have the capacity to operate both existing freight
rail and more frequent passenger service. A second option, building new commuter
railway tracks within the BNSF right of way, has significant environmental and
cost impacts. Commuter trains would be slowed by priority BNSF freight trains,
which would not improve transit performance in the project area. The project
also considered a new railway corridor, but it would have significant right of
way impacts.

Commuter rail was also ruled out because of difficulties providing
connections to existing bus and light rail systems and key activity centers like
downtown Portland. Commuter rail is most effective at reducing congestion in
areas with few stops and distances greater than the five-mile Columbia River
Crossing project area.

Ferry

A ferry service between downtown Vancouver and downtown Portland would be
slower than other transit modes and would not improve congestion.

Streetcar

This slower type of transit service cannot serve the region’s existing or
future population and would not improve congestion if constructed to serve the
Vancouver to Portland commuter market.

Bus rapid transit

Bus rapid transit carries fewer riders per vehicle. Thus, more vehicles would
be needed to serve the demand
for transit across the Columbia River, adding to the cost of operations and
maintenance. Transit riders also would be required to transfer at the Expo
Center to connect to the existing light rail system, adding up to five minutes
of travel time delay.

HIGHWAY

Reversible lanes

Reversible lanes, like those on I-5 in Seattle, require added shoulders and
barriers compared to regular highways. This increased width could have greater
impacts on right of way in downtown Vancouver. Reversible lanes also perform
better as part of a larger, regional system; they would not relieve congestion
significantly in CRC’s five-mile project area.

I-205 capacity improvements

Between 68 and 75 percent of traffic on the I-5 bridge enters or exits the
highway within the project area, which does not include the I-205 corridor. To
address congestion and safety deficiencies, improvements must be made to I-5
itself.